Add group level present in aggregate Jacoco report

[mourezwell]

Hi, Thanks for the script, I just had to add group level present in aggregate reports https://www.eclemma.org/jacoco/trunk/doc/report-aggregate-mojo.html as defined in DTD http://www.eclemma.org/jacoco/trunk/coverage/report.dtd

Note : my fork includes captainmalloc work on python3 compatibilty

[trumpetx]

I can confirm that this fix works great for the multi-module report

[exabrial]

Also much neededd, thank you!